Apparatus and Method for Cutting Tubular Members

ABSTRACT

A method of cutting a continuous hollow tubular member having a fully expanded configuration with an outer diameter D, includes the steps of feeding the continuous hollow tubular member in the fully expanded configuration to a cutting station, cutting the continuous hollow tubular member into a plurality of hollow tubular members, each of which has a first flattened end and expanding the first flattened end of the plurality of hollow tubular members to the fully expanded configuration such that the first end of the plurality of hollow tubular members has an outer diameter D.

FIELD OF THE INVENTION

The present invention relates to an apparatus for cutting tubularmembers and, in particular, an apparatus for cutting tubular members asthey are continuously produced such as, for example, by an extrusionprocess.

BACKGROUND AND SUMMARY OF THE INVENTION

Various machines and apparatus for cutting tubular members are known.Examples of these include U.S. Pat. No. 6,736,409 entitled DrinkingStraw Prepared From Flattened Polymeric Tubular Conduit, Method ofMaking Same and Dispenser Therefor; U.S. Pat. No. 7,549,854 entitledStriped Drinking Straw and Method of Making Same, U.S. Pat. No.4,212,215 entitled Apparatus For Cutting a Tube of Semi-Rigid Materialand U.S. Patent Application Publication No. US 2006/0086228 entitledTube Cutting Process and Device. Devices for packaging or handling cuttubular members are disclosed in U.S. Patent Application Publication No.US 2006/0026930 entitled Dual Head Straw Wrapper and U.S. Pat. No.3,648,553 entitled Device for Transporting Elongated Work Pieces.

In one embodiment of the present invention, an apparatus for cuttingtubular members includes a support structure, a control system, acutting station, a guide and an extracting assembly. The cutting stationincludes a first wheel having at least one cutting member located on thecircumference of the first wheel and a second wheel having at least oneprojection located on the circumference of the second wheel. Theextracting assembly has a cylindrical member with a first end and asecond end. The cylindrical member also includes a first interiorsection tapering from the first end toward the second end, a secondinterior section tapering from the end of the first interior sectiontoward the second end of the cylindrical member, a third interiorsection extending from the end of the first interior section toward thesecond end of the tubular member and a pair of grooves extending fromthe first interior section to the third interior section. The groovesdecrease in height and depth from the first interior section to thethird interior section.

In another embodiment of the present invention, an apparatus for cuttingtubular members includes a cutting station and an extracting assemblyfor ejecting the cut segments of the tubular member from the apparatus.The extracting assembly includes at least one groove for expanding aportion of the cut segments.

In another embodiment of the present invention, an apparatus for cuttingtubular members includes a cutting station and an extracting assembly.The cutting station has a first wheel and a second wheel. The firstwheel has at least one cutting member located on its circumference. Thecutting member has a portion for cutting the tubular member. The secondwheel has at least one projection located on its circumference. Thefirst and second wheels are positioned such that the portion for cuttingthe tubular member and the projection are aligned on opposite sides ofthe tubular member when it is cut without the portion for cutting thetubular member contacting the projection.

In another embodiment of the present invention, a method of cutting atubular member, includes the step of introducing a tubular member intoan apparatus having a cutting station, the cutting station having afirst wheel having at least one cutting member located on thecircumference of the first wheel, the cutting member having a cuttingportion and a second wheel having at least one projection located on thecircumference of the second wheel. The method further includes the stepsof guiding the tubular member between the first and second wheels androtating the first and second wheels such that the cutting portion ispositioned opposite the projection and has a tangential speedsubstantially equal to the linear speed of the tubular member whilecutting the member.

In another embodiment of the present invention, a method of cutting acontinuous hollow tubular member having a fully expanded configurationwith an outer diameter D, including the steps of feeding the continuoushollow tubular member in the fully expanded configuration to a cuttingstation, cutting the continuous hollow tubular member into a pluralityof hollow tubular members, each of which has a first flattened end andexpanding the first flattened end of the plurality of hollow tubularmembers to the fully expanded configuration such that the first end ofthe plurality of hollow tubular members has an outer diameter D.

In other embodiments, the method further includes cutting the continuoushollow tubular member into a plurality of hollow tubular members havinga second flattened end and a section located between the first flattenedend and the second flattened end. The section located between the firstflattened end and the second flattened end has an outer diameter D.

In other embodiments, the method includes expanding the second flattenedend of the plurality of hollow tubular members to the fully expandedconfiguration such that the second end of the plurality of hollowtubular members has an outer diameter D.

In one embodiment, the second flattened end is formed prior to expandingthe first flattened end.

In another embodiment, the step of expanding the first flattened endincludes engaging the first flattened end with a groove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of an apparatus for cutting tubularmembers according to one embodiment of the present invention.

FIG. 2 is a top plan view of the apparatus for cutting tubular membersshown in FIG. 1.

FIG. 3 is an enlarged perspective view of the cutting station andextracting assembly that are features of the apparatus for cuttingtubular members shown in FIG. 1.

FIG. 4 is a perspective view of the extracting assembly shown in FIG. 3.

FIG. 5 is a cross-sectional view of a portion of the extracting assemblytaken along line 5-5 in FIG. 4.

FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 4.

FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 4.

FIG. 8 is a perspective view of a segment of a tubular member cut by theapparatus for cutting tubular members shown in FIG. 1 before it haspassed through the extracting assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a front elevational view of an apparatus for cutting tubularmembers (also referred to as a tubing cutter) according to oneembodiment of the present invention. Tubing cutter 10 generally includesa support structure 20, a control system 30, a guide 40, a cuttingstation 50 and an extracting assembly 60.

In the embodiment shown, support structure 20 includes a generally boxshaped base 21 having a plurality of wheels 22 and a plurality ofsupports 23. Supports 23 include threaded sections 23A which terminateat one end in feet 23B. Threaded sections 23A extend through nuts 24 onbase 21. As will be apparent to one of ordinary skill in the art,supports 23 can be advanced upward through nuts 24 to raise feet 23B,thereby allowing tubing cutter 10 to be moved by rolling it on wheels22. When tubing cutter 10 is placed in the desired location, supports 23are advanced in the opposite direction until feet 23B engage the groundand adequately stabilize tubing cutter 10. Base 21 houses certain of theelectronic and other components that control the operation of tubingcutter 10 as described below.

Control system 30 includes a variety of controls (not shown) that arethe interface through which the operator controls operation of tubingcutter 10. For example, control system 30 can include buttons, switches,knobs and other devices for powering the various components of tubingcutter 10 on and off, changing the operating speed and controlling otherfunctions.

In the embodiment shown, guide 40 includes a funnel 41 having its largerfirst end 42 positioned farther from cutting station 50 than its smallersecond end 43. Second end 43 attaches to tube 44 which extends through abracket 45 adjacent cutting station 50. An end 46 of tube 44 terminatesadjacent the components used for cutting the tubular member as shown inFIG. 3 and as described in greater detail below.

Cutting station 50 includes a cover 51 (shown as transparent in FIGS. 1and 2). FIG. 3 shows cutting station 50 with cover 51 removed. As shownin FIG. 3, cutting station 50 includes a first wheel 52 having aplurality of cutting members 53 disposed about the circumferencethereof. In the embodiment shown, wheel 52 includes three cuttingmembers 53 (two of which are shown in FIG. 3) spaced equally around thecircumference, i.e., 120° apart. In the embodiment shown, cutting member53 is a substantially flat, straight die similar to those known for usein die cutting boxes and other flat paper products. In one embodiment ofthe invention, cutting members 53 are placed within recesses (not shown)in wheel 52 sized to accommodate cutting members 53. Cutting members 53may be secured to wheel 52 in a number of manners. In one embodiment,cutting members 53 are secured to wheel 52 by magnets placed beneath oradjacent the recesses or otherwise positioned in or near wheel 52.Cutting station 50 also includes a second wheel 54 that includes aplurality of lobes or projections 55 spaced equally around thecircumference of wheel 54. The cutting station 50 includes the samenumber of cutting members 53 and projections 55 spaced at the sameinterval about the circumference of wheels 52 and 54. The wheels 52 and54 are secured to shafts 56 by collars 57. Shafts 56 are coupled to thedrive shaft of drive mechanisms 58. Although various drive mechanisms 58can be used, one embodiment of the present invention utilizes two servomotors to rotate wheels 52 and 54. The various components of cuttingstation 50 are secured to base 20 and supported thereon by supportstructure 59. Note that a portion of support structure 59 includes anelongated opening 59A. Support structure 59 also supports a rotatablehandle 59B. Handle 59B is mechanically coupled to a slide mechanism (notshown) such that rotating handle 59B moves wheel 52 vertically. Opening59A accommodates movement of wheel 52 and its associated shaft 56.

Extracting assembly 60 generally includes a tube 61 and a pair ofgripping members 62 driven by drive mechanism 63. In the embodimentshown, gripping members 62 are horizontally mounted wheels driven bydrive members 63. Drive members 63 can be any of a number of knownmechanisms capable of rotating gripping members 62 on shafts 63A. Tube61 extends through bracket 64 as shown in FIG. 3 and includes a firstend 61A and a second end 61B. As shown in FIG. 4, tube 61 includes aplurality of openings 65 into which gripping members 62 extend to engagethe cut tubular member as described in greater detail below. Extractingassembly 60 also includes a pair of slide mechanisms 63B and handles 63C(FIG. 4). Rotating handles 63C causes slide mechanisms 63B to movetoward or away from tube 61, thereby moving gripping members 62 furtherinto or out of openings 65. Handles 63C can be provided with a lockingmechanism, such as a set screw.

Referring to FIGS. 4-7, tube 61 includes a first interior section 66A, asecond interior section 66B, a third interior section 66C, a fourthinterior section 66D and a fifth interior section 66E. Section 66Atapers as shown from first end 61A toward second end 61B of tube 61.Second interior section 66B likewise tapers in the same direction. Apair of grooves 67 are formed in interior sections 66A, 66B and 66C andhave a first end 67A and a second end 67B. Grooves 67 decrease in heightand depth from end 67A toward end 67B, eventually terminating in section66C.

In use, tubing cutter 10 is utilized to cut a tubular member 70 as it iscontinuously fed into the cutting station 50. In particular, tubingcutter 10 can be used to cut a continuously extruded tubular member into sections to produce various items, such as drinking straws. Inoperation, the tubular member 70 is fed into end 42 of funnel 41, guidedthrough tube 44 and exits end 46 adjacent wheels 52 and 54 as shown inFIG. 3. Control system 30 is utilized to rotate wheels 52 and 54 suchthat when cutting member 53 engages tubular member 70 to cut it,projections 55 are positioned beneath cutting members 53. The cuttingportion of cutting member 53 extends through tubular member 70sufficiently to cut it without contacting projection 55. The rotation ofwheels 52 and 54 are controlled such that the tangential speed of thecutting portion of cutting members 53 is the same as the linear velocityof the tubular member 70 being cut when the cut is made. The length ofthe cut section of tubular member 70 can be varied in a number of ways.For example, utilizing more than three cutting members 53 andprojections 55 would result in shorter cut segments having a shorterlength. In an alternative embodiment, wheels 52 and 54 do not rotate ata constant speed. Rather, they could be stopped between cuts and thenrotated to produce different length cut tubular members. Alternatively,their speeds could be accelerated or decelerated between cuts andaccelerated or decelerated such that the speed of cutting member 53matches the speed of tubular member 70 at the desired time to produce acut segment of desired length.

FIG. 8 is a perspective view of a cut segment 70A of tubular member 70before it has passed through extracting assembly 60. As shown in FIG. 3,when certain materials are cut, the cut ends 71 and 72 can be flattenedduring the cutting process. After the cut is made, end 71 enters end 61Aof tube 60. The tapered configuration of the interior sections of tube61 guide end 71 such that it engages grooves 67 at ends 67A, which issized and configured to be wider and higher than end 71. As end 71 ridesin grooves 67, it is forced open by the tapered configuration of thedecreasing depth of grooves 67. Thus, the end 71 is open andsubstantially circular when the cut segment 70A exits tube 61 at end61B. Note grooves 67 also open trailing end 72 of the cut segment 70A ina similar fashion. Depending on the material from which tubular member70 is made, the speeds at which the cut segments 70 travel through tube61 and the number of cut segments processed, grooves 67 can eventuallywear and no longer serve their intended purpose. Accordingly, it may bedesirable to make tube 61 from a relatively hard, wear resistantmaterial, such as 440C stainless steel. Other materials can also beused. Alternatively, softer materials can be used but tube 61 may needto be replaced more frequently.

As end 71 reaches opening 65, gripping members 62 engage cut segment 70Aand eject it from end 61B. Note that end 61B includes a plurality ofopenings 61C. If desired, a guide tube can be inserted in to interiorsection 66E and secured in place by inserting bolts or other fastenersthrough openings 61C. The guide tube can be used to further direct thepath of travel of cut segments 70A.

Although the present invention has been shown and described in detail,the same is for purposes of illustration only and is not a limitation onthe invention. Numerous modifications to the invention can be made. Forexample, the locations of wheels 52 and 54 can be reversed. Handle 59Bcould be replaced with a motor or other automated means for moving wheel52. Wheel 52 could be stationary and wheel 54 moveable, or both could bemoveable. The length and inner configuration of tube 61 can also bechanged based on the product being cut. Various guide mechanisms otherthan funnel 41 and tube 44 can also be used. It is also not necessarythat tubing cutter 10 be movable. Rather, cutting station 50 andextracting assembly 60 can be secured to a stationary structure.

I claim:
 1. A method of cutting a tubular member, including the stepsof: introducing a tubular member into an apparatus having a cuttingstation, the cutting station having a first wheel having at least onecutting member located on the circumference of the first wheel, thecutting member having a cutting portion and a second wheel having atleast one projection located on the circumference of the second wheel;guiding the tubular member between the first and second wheels; rotatingthe first and second wheels such that the cutting portion is positionedopposite the projection and has a tangential speed substantially equalto the linear speed of the tubular member while cutting the member. 2.The method of claim 1, wherein the cutting portion does not contact theprojection as the tubular member is cut.
 3. The method of claim 1,further including the step of varying the rotational speed of at leastone of the first and second wheels.
 4. The method of claim 3, furtherincluding the step of introducing the tubular member between the firstand second wheels at a substantially constant linear velocity.
 5. Themethod of claim 1, further including the step of expanding a portion ofthe cut tubular member.
 6. The method of claim 1, further including thestep of inserting a portion of the cut tubular member into a groove toexpand a portion of the cut tubular member.
 7. A method of cutting acontinuous hollow tubular member having a fully expanded configurationwith an outer diameter D, including the steps of: feeding the continuoushollow tubular member in the fully expanded configuration to a cuttingstation; cutting the continuous hollow tubular member into a pluralityof hollow tubular members, each of which has a first flattened end; andexpanding the first flattened end of the plurality of hollow tubularmembers to the fully expanded configuration such that the first end ofthe plurality of hollow tubular members has an outer diameter D.
 8. Themethod according to claim 7, further including cutting the continuoushollow tubular member into a plurality of hollow tubular members havinga second flattened end and a section located between the first flattenedend and the second flattened end, the section located between the firstflattened end and the second flattened end having an outer diameter D.9. The method according to claim 8, further including expanding thesecond flattened end of the plurality of hollow tubular members to thefully expanded configuration such that the second end of the pluralityof hollow tubular members has an outer diameter D.
 10. The methodaccording to claim 8, wherein the second flattened end is formed priorto expanding the first flattened end.
 11. The method according to claim7, wherein the step of expanding the first flattened end includesengaging the first flattened end with a groove.